possibility of bad replacement coils

I recently purchased a nautilus mini and love it, that being said i am experiencing some issues and cant seem to work out the cause...I use an Ego-V V3 Mega battery, set around 4-4.2v, and for the first couple months i have had no issues. However now it doesn't seem to be working. When i push the button it lights up for a second and then flashes 3 times, no vapor being produced from the unit. i have eliminated that the issue is being caused by the battery because I've tested the same battery with different tanks including my friends nautilus mini and it works flawlessly. The only other idea i could think of is that i recently burnt through the 2nd coil i received with my tank and had to purchase a 5 pack of replacements from a local vape shop. they are genuine aspire coils, i can provide the numbers on the side of the pack if it will help you to determine if the coils could be the cause....Any information will be greatly appreciated, I would love to resolve this and continue to use and promote your product as what i consider to be the best.

Dear Customer,Thank you for supporting aspire!Please make sure you bought original nautilus mini and coils,not only just by checking the security code,but also by checking the packaging and print.For your problem,here is our engineer's suggestion:First,change another coil to have a try.if problem be solved,it maybe,at the process of the coil be screwed into the base hardware,the interior structure was damaged unconscious ,which caused the short out.If not,please use the base hardware from your friends' nautilus mini to assemble your nautilus mini tank,if the problem be solved,it maybe the connector/insulated pin has Aged you need have a new one.Here are our chief engineer suggestion to use our products correctly:Some people asked that why we invented coils with different resistance coils ,not only for offering customer some different choose,but also because different resistance coils have different voltage and applicative battery requirement to make the coils work properly.For our 1.6ohm coils,the reasonable voltage is:3.3V-4.2V,use it with normal e-go battery,which have constant voltage output.For our 1.8ohm coils,the reasonable voltage is:4.2V-4.8V,use it with voltage adjustable battery,never use our 1.8 ohm coils with high-power wattage adjustable Mod,if once customer to use our coils with wattage exceed 15W Conscious or non conscious.the structure will be damaged,despite how low wattage customer used later,the burn taste will never solved.What's more,high proportion of VG e-juice or high sugar/sweetener content e-juice will also affect the coils life.we suggest to use our products with VG proportion less than 50%Thank you and have a nice day!